The invention relates generally to injection molding systems, and more particularly to improved pressure bushing locating rings therefor and combinations thereof.
Injection molding systems are known and comprise generally a hydraulic or electric injection molding machine coupled to one or more mold cavities. The injection molding machine and more particularly an extrusion nozzle thereof supplies a molten material, usually plastic, to the one or more mold cavities through a cold or hot runner system.
In some injection molding systems, the extrusion nozzle seats on a pressure bushing disposed between the injection molding machine and the hot or cold runner system. In FIG. 3 of the present application, an injection molding system 10 comprises a pressure bushing 12 coupled to a hot tip system 19 by a prior art locating ring 14 fastened to a clamp plate 16 by several bolts 18 engaged therewith. In these and other injection molding system configurations, the extrusion nozzle of the injection molding machine, not illustrated in FIG. 3, seats on an input side 13 of the pressure bushing 12 and injects molten material through the pressure bushing and into the mold cavities. In many other systems a distribution manifold supplies the molten material to several hot runner systems.
In some molding operations however the immense pressure exerted on the mold cavity side of the pressure bushing 12 by the molten material supplied therethrough urges the locating ring away from the clamp plate 16 to such an extent that the bolts or locating ring may become deformed or that molten material leaks from in and around the pressure bushing. In some cases, the pressure is so great that the bolts 18 retaining the locating ring 14 on the clamp plate 16 fail by breaking.
The present invention is drawn toward advancements in the art of injection molding systems, and more particularly to novel pressure bushing locating rings and combinations thereof.
An object of the invention is to provide novel injection molding systems and novel pressure bushing locating rings therefor that overcome problems in the art.
Another object of the invention is to provide novel injection molding systems and novel pressure bushing locating rings that are robust and economical.
Another object of the invention is to provide novel injection molding systems and novel pressure bushing locating rings that are less likely to fail under pressure exerted by molten material supplied through the pressure bushing retained thereby.
A further object of the invention is to provide novel injection molding systems having novel pressure bushing locating rings disposed between a clamp plate and a platen, whereby the platen supports at least a portion of the locating ring.
A more particular object of the invention is to provide novel injection molding systems comprising generally a locating ring disposed about and engaged with a pressure bushing. A first side of the locating ring is disposed against the outer surface of the clamp plate and an opposing second side of the locating ring is disposed against the platen, thereby supporting the locating ring. The first side of the locating ring is preferably disposed in a recessed mounting surface on the clamp plate and at least a portion of the second side of the locating ring is flush with the outer surface of the clamp plate so that both the clamp plate and radial outer portion of the locating ring are engaged with the platen.
These and other objects, aspects, features and advantages of the present invention will become more fully apparent upon careful consideration of the following Detailed Description of the Invention and the accompanying Drawings, which may be disproportionate for ease of understanding, wherein like structure and steps are referenced generally by corresponding numerals and indicators.